Add VM device hot attach/detach support

Adds a new API endpoint to support hot attach/detach of devices, and the
corresponding client-side logic to use this endpoint when doing VM
network/storage add/remove actions.

The live attach is now the default behaviour for these types of
additions and removals, and can be disabled if needed.

Closes #141

api-daemon/pvcapid/flaskapi.py

@@ -2003,6 +2003,72 @@ class API_VM_Rename(Resource):
 api.add_resource(API_VM_Rename, '/vm/<vm>/rename')
 
 
+# /vm/<vm>/device
+class API_VM_Device(Resource):
+    @RequestParser([
+        {'name': 'xml', 'required': True, 'helptext': "A Libvirt XML device document must be specified"},
+    ])
+    @Authenticator
+    def post(self, vm, reqargs):
+        """
+        Hot-attach device XML to {vm}
+        ---
+        tags:
+          - vm
+        parameters:
+          - in: query
+            name: xml
+            type: string
+            required: true
+            description: The raw Libvirt XML definition of the device to attach
+        responses:
+          200:
+            description: OK
+            schema:
+              type: object
+              id: Message
+          400:
+            description: Bad request
+            schema:
+              type: object
+              id: Message
+        """
+        return api_helper.vm_attach_device(vm, reqargs.get('xml', None))
+
+    @RequestParser([
+        {'name': 'xml', 'required': True, 'helptext': "A Libvirt XML device document must be specified"},
+    ])
+    @Authenticator
+    def delete(self, vm, reqargs):
+        """
+        Hot-detach device XML to {vm}
+        ---
+        tags:
+          - vm
+        parameters:
+          - in: query
+            name: xml
+            type: string
+            required: true
+            description: The raw Libvirt XML definition of the device to detach
+        responses:
+          200:
+            description: OK
+            schema:
+              type: object
+              id: Message
+          400:
+            description: Bad request
+            schema:
+              type: object
+              id: Message
+        """
+        return api_helper.vm_detach_device(vm, reqargs.get('xml', None))
+
+
+api.add_resource(API_VM_Device, '/vm/<vm>/device')
+
+
 ##########################################################
 # Client API - Network
 ##########################################################

api-daemon/pvcapid/helper.py

@@ -491,6 +491,58 @@ def vm_define(zkhandler, xml, node, limit, selector, autostart, migration_method
     return output, retcode
 
 
+@ZKConnection(config)
+def vm_attach_device(zkhandler, vm, device_spec_xml):
+    """
+    Hot-attach a device (via XML spec) to a VM.
+    """
+    try:
+        _ = etree.fromstring(device_spec_xml)
+    except Exception as e:
+        return {'message': 'XML is malformed or incorrect: {}'.format(e)}, 400
+
+    retflag, retdata = pvc_vm.attach_vm_device(zkhandler, vm, device_spec_xml)
+
+    if retflag:
+        retcode = 200
+        output = {
+            'message': retdata.replace('\"', '\'')
+        }
+    else:
+        retcode = 400
+        output = {
+            'message': 'WARNING: Failed to perform hot attach; device will be added on next VM start/restart.'
+        }
+
+    return output, retcode
+
+
+@ZKConnection(config)
+def vm_detach_device(zkhandler, vm, device_spec_xml):
+    """
+    Hot-detach a device (via XML spec) from a VM.
+    """
+    try:
+        _ = etree.fromstring(device_spec_xml)
+    except Exception as e:
+        return {'message': 'XML is malformed or incorrect: {}'.format(e)}, 400
+
+    retflag, retdata = pvc_vm.detach_vm_device(zkhandler, vm, device_spec_xml)
+
+    if retflag:
+        retcode = 200
+        output = {
+            'message': retdata.replace('\"', '\'')
+        }
+    else:
+        retcode = 400
+        output = {
+            'message': 'WARNING: Failed to perform hot detach; device will be removed on next VM start/restart.'
+        }
+
+    return output, retcode
+
+
 @pvc_common.Profiler(config)
 @ZKConnection(config)
 def get_vm_meta(zkhandler, vm):